Tibetan exiles say Chinese authorities have expanded a re-education campaign in the restive county of Driru by locking down at least three monasteries and calling back locals who were studying outside of the Tibetan Autonomous Region (TAR).

A letter from the area, received by exiled Tibetans who have been observing the situation, said a mass “mental re-education” campaign was being extended in Driru, known as Biru in Chinese, site of recent unrest.

The letter and information received by exiled Tibetans from Driru said the soldiers arrived at the Tarmo Monastery late last month shortly after three monks from that monastery were arrested in Lhasa. The sources said the soldiers took phones, computers, books and old knives.

Photos obtained by VOA's Tibetan service showed lines of military trucks parked bellow what was described as the Tarmo Monastery.

At least eight monks from Rabten Monastery in Driru, who had been studying in Granze prefecture, were arrested and put in a county detention center in Driru, according Shidre, a Dharamsala based Driru observer, who uses a pseudonym.

Meanwhile, the Drongna Monastery in Driru was surrounded by Chinese soldiers recently, but it is not known if the action was temporary or ongoing.

Samdup, a Tibetan from Driru who lives in Belgium, told VOA's Tibetan service about 1,000 people from Driru have been detained since September.

“They are concerned that if Driru is not stabilized first, it could destabilize the entire Tibetan Autonomous Region,” said Samdup.

In August, the government in the Tibetan Autonomous Region launched a special patriotic campaign in Driru. The following month villagers were ordered to fly Chinese national flags from their rooftops. But people in at least two villages reportedly dumped the flags into a river.

Since then, there have been reports of protests, arrests and shootings by police.

Tibetan exiles with close links to Driru say the situation remains tense and arrests are continuing.

Last month, a report from the U.S. Congressional Executive Commission on China said the Chinese government was taking recent unrest in the Tibetan Autonomous Region very seriously.

The report concluded that the way Chinese security forces had responded to protests in Driru County reflected a strong desire to ensure that such incidents remained isolated.

(This report was produced in collaboration with the VOA Tibetan service.)